The long-term objective of this research is to develop a device that will improve the efficacy of cryopreserving cells in suspension and small pieces of tissue. Having improved means for cell and tissue cryopreservation can increase the effectiveness of bioresource centers containing banks of high quality cells and tissues for research. It can also provide cryopreserved cells for direct patient therapy (e.g. oocytes and ovarian tissue for fertility preservation, stem cells and pancreatic islets for transplantation). The objectives of this Phase I application are to develop a microfluidics cryopreservation system based upon an existing system designed for cell culture and imaging. The current system will be significantly modified in a manner that will allow it to deliver precise concentrations of solutions containing cryoprotectants at temperatures ranging from + 37 to -20 degrees C for cryopreservation of suspended cells. This will facilitate rapid cryoprotectant diffusion into cells before cryopreservation, and dilution out of cells after cryopreservation. It will also allow cells to be exposed to cryoprotectants at reduced temperatures, mitigating chemical toxicity. The aims of this project are to determine means to rapidly mix combinations of solutions and to determine the appropriate flow rates for solutions of varying viscosity. We also plan to design a new microfluidics chip specifically for cryopreservation applications as well as a cooling unit to accompany the existing hardware;a capability that the current device lacks. Mixing will be assessed by analysis of digital images taken of the solution in the final flow path, where metallic microspheres have been suspended into one of the initial solutions. Appropriate flow rates will be determined by assessing the properties of microspheres suspended in the solutions during flow. With such an instrument, high throughput cryopreservation for suspended cells and small tissue can be accomplished, significantly reducing the financial and technical burden associated with cryopreserving laboratory animal germplasm, and also offers a more accurate and reproducible means to archive cells and tissues for research and therapeutic uses. PUBLIC HEALTH RELEVANCE: The proposed research is designed to develop a device that will facilitate making improvements in methods to preserve cells and small pieces of tissue using very low temperatures (cryopreservation). Cryopreserved cells and tissues are important for many reasons, such as direct medical therapy (e.g. transplantation of blood cells), and also for providing consistent biological samples for scientific study by numerous researchers (e.g. when studying cancer or other chronic diseases). Such a device will also significantly increase the efficiency of cryopreserving germplasm from laboratory animals, reducing the overall costs to public agencies for storage and distribution of these valuable research tools.